Retro Fits: Older Machines, Younger Control Systems

A Few Subtle Upgrades Might Be All It Takes to Make That Old Machine Perform Like New

By Jim Montague

October 2011 IssueJust as there's more than one way to skin a cat, there's more than one way to successfully revive a relationship — including rejuvenating solid, older machines and equipment with innovative, younger control systems and capabilities.

Just as human relationships evolve in ways both subtle and obvious, familiar automation and control devices often can be applied in new ways and in settings where they hadn't been used before. So, while there's nothing like new friendship and discovering automation's advantages over manual processes, even old buddies and long-time automation users find they can renew their relationships with their machines and equipment with some new functions, usually enabled by newer controllers, better software, improved data processing, more pervasive networking or a suitable combination of each, depending on the needs of a particular application.

Improving PLCs

RockTenn's printing plant in Jacksonville, Fla., goes through more than 900 huge rolls of paper per month, and prints the outsides of pasteboard cartons that will contain beer, yogurt, drink pouches and other products. The plant's press is 14 ft wide and nearly 150 ft long (Figure 1), and was built by Cobden Chadwick (now Chadwick Web Processing), based in Heywood, U.K. The paper is threaded through the machine and around a huge temperature-controlled cylinder. After printing, the paper passes through a dryer and an inspection station, and then is re-rolled. The now-obsolete PLCs monitored and controlled the entire press from a central location.

The plant's automation systems became increasingly unreliable as the obsolete and costly PLCs generated too many false alarms, and couldn't give feedback about problem locations or provide diagnostics. "To find a fault, the plant's staff had to waste time physically testing each interlock until they could locate it," says Andy Banaczyk, RockTenn's maintenance director, who initially replaced one of the old PLCs with a new PLC, touchscreen and software. This initial project went so well that Banaczyk decided to replace all the PLCs in the plant and add communications to let them share status data, but knew he would need some help.

RockTenn's management, general manager Greg Hoag and plant manager Peter D'Angelo, supported the plant's improvement and upgrade, so Banaczyk enlisted help from system integrators W.L. Smith Electronics, which built enclosures and programmed PLCs, and Expert Automation Design (EAD), which retrofitted legacy PLCs, migrated older PLC programs to newer software, and implemented a new data network. They selected their hardware primarily from AutomationDirect.

"We didn't have the original PLC code and had no way to convert the old code, so we had to rewrite the control and safety code for each new PLC," says Glenn Erickson, EAD's president. "However, using DirectSoft programming software made this fairly simple and straightforward. For example, Andy implemented a voice-broadcast system using the audio capabilities of the C-more touchscreen, and recorded messages tied to specific actions or operations."

Some of the PLCs control temperature, safety systems and press operations, while others monitor press operations, but now all of them can pass and exchange data as needed in a peer-to-peer network with no PLC acting as a master device. This configuration allows the new systems to be more reliable because there's no single point of failure, Erickson adds. So far, RockTenn's plant has gained 30 new PLCs with nearly 2,500 corresponding I/O points. The plant also replaced many of the former pushbuttons, selector switches and indicator lights.

Though the new PLCs replaced almost all the plant's existing controls, an old stepper-control PLC still controls the impression rollers and ink rollers, but it's scheduled to be replaced soon, too. All of the other automation systems for the physical components of the ink-supply system have been upgraded already.

"We set up a communications system, so all the PLCs in the building, with a few minor exceptions, are linked by Ethernet. We can call up any linked PLC and monitor its status or make changes to the PLC logic, all from any of several PCs around the plant," Erickson explains. "The entire system is also tied to a PC running DirectSoft, which allows Internet access and enables any authorized person to log in, monitor the system, or make changes. This has reduced downtime and service calls."

Because the press is ringed with safety gates and interlocks, this upgrade project also included the safety system. "This further reduced unnecessary stoppages to the point they can now be counted on one hand during a 12-month period," Banaczyk says. "I couldn't count the number of stoppages we used to have. I just know it was a nightmare before, and now we have no problems."

When a rare stoppage does occur, the plant's new automation system announces at the main control panel where the fault is located on the press. "With fewer safety system faults and quick resolution of fault causes, this item has dropped off the charts as an area of concern," Erickson adds.

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More, Better Motion

Besides replacing basic controllers and software, legacy machines can interact with other modern control technologies when the need is for improved motors and motion solutions.

Glen Carbon, Ill.-based system integrator FASTechnology Group recently helped rebuild three machines that form a binding operation at Arandell, a magazine and catalog printer in Menomonee Falls, Wis. This 30-year-old adhesive binding system still had a solid framework and mechanicals, but its controls were worn out and obsolete. This made it almost impossible to add new functions while still maintaining integrated controls and communications, so Arandell asked FASTech to upgrade the gatherer, binding, trimming and conveying stages of its three-machine system.

The integrator added an automatic lubrication system to the main drive chain with a user-settable application interval, and then installed a marquee for alarm annunciation and two 20-character overhead displays to enable a clear view of machine status from anywhere near it.

However, FASTech's primary goal was to implement on-the-fly phasing between the binding system's motors, each of which controlled a section of the multi-staged conveyor. Arandell wanted adjustable product hand-off points between each conveyor section, and so full motion control integration of up to 10 conveyor sections was needed, as well as elimination of a clutch assembly between the two sections. Before the retrofit, these two sections were driven by one motor, equipped with one planetary gear between them. This motor was replaced with two motors, and the planetary gear was replaced with an electronic line shaft to provide better product transfer control between the two sections and a smoother transition at a wider range of machine speeds (Figure 2).

"We determined our architecture needed to be very flexible, expandable, and easy to install, set up and operate for the customer's personnel," says Dave Carlos, FASTech's vice president of sales and marketing. "Because so many on-the-fly handling and transition modifications are present in the magazines and catalogs produced at Arandell, we also had to make the system work at a very cost-effective level."

Arandell reports that its new motion-control platform and onsite training from FASTech enabled its overall binding system throughput to improve by 20%. Also, the new system can be more easily modified by Arandell's operators, who were cross-trained to run multiple machine sections of the overall machine.

The three machines that FASTech updated all used Siemens' Sinamics S120 drive and Simotion D drive platform, which combined motion control, logic control and drive control into one system that now essentially serves as each machine's controller. With help from a complementary HMI and other hardware, this drive system functions as a common platform/interface for the whole bindery operation. This simplification allows Arandell to keep fewer spare parts in stock. Likewise, the plant's communications were enhanced by moving the entire system to one Profibus network. Finally, Sinamics drives integrate all of the machines' functions with their safety controls.

"Simotion architecture, with its integrated motion controller and PLC controller, allowed us to perform advanced motion control along with normal PLC-level logic," explains Jeff Mills, FASTech's engineering vice president. "The modularity of the line we chose further allowed us to take the functionality we had developed for our customer and apply it elsewhere on similar machine retrofits. In fact, we recently used this platform to do rebuilds on four perfect binders, seven saddle stitchers, four stackers, a standalone trimmer and mail table, plus numerous machines outside the commercial printing industry."

Old, New and Safety, Too

Not content to merely integrate older machines with new controls, many builders incorporate new and critical capabilities, such as increased safety functions. Hampshire Tobacco Machinery Services (HTMS) in Romsey, U.K., supplies and reengineers cigarette packaging equipment, focusing mainly on hard-box, hinge-lid packing machinery. One of its primary challenges is bringing older machines, some built during the 1940s, up to compliance with modern safety rules such as the new EN ISO 13849-1 Functional Safety standard.

For example, while refurbishing and replacing the controls in a cigarette packaging machine built in the 1980s, HTMS sought to minimize the project's expenses by combining its regular automation and safety components on a common network, which has been an increasingly popular U.S. strategy since the National Fire Protection Assn. (NFPA) revised its NFPA-79 rules to allow it.

"Closely linking automation and safety reduces wiring, enables single-platform training and programming, reduces 'between-systems' data bottlenecks, and cuts overall costs," says Pete Woodthorpe, HTMS's technical director.

To combine its old packing machine's automation and safety components, HTMS eventually settled on Rockwell Automation's MicroLogix 1200 PAC connected with a SmartGuard 600 programmable safety controller to simultaneously automate the machine and certify that its safety system meets EN ISO 13849-1. The upgrade also used RSNetWorx software, RFID-coded safety interlock switches, safety contactors and soft starters, and Sistema performance-level (PL) calculator software. Developed by the Germany-based Institute for Occupational Safety and Health of the German Social Accident Insurance (IFA), Sistema helps developers and testers of safety-related machine controls evaluate their safety in the context of EN ISO 13849-1. The tool lets users model the structure of their safety-related control components based on designated architectures, which permits automated calculation of reliability values with various levels of detail, including that of the PL attained.

"The basic approach to evaluating the machine's safety is similar to how we used to do it, but the Sistema software lets us assess it by areas or modules, which is unlike the old way where we looked at the machine as a whole," Woodthorpe adds. "Our assessment process is simpler and made easier by having all the equipment in the Sistema library, so we just drag and drop components into the application. You can almost immediately see if there are any safety issues."

Rebuilding the Builder

Most times retrofitting old machines just means installing new hardware or controls, but sometimes increased demand for particular types of products and the promise of a steady stream of projects can draw builders into a whole new technical area, and even inspire them to reorganize and rebuild the company itself.

Manifold & Phalor in Canal Winchester, Ohio, is a traditional job shop and machine builder, mostly of glass processing equipment. However, when a longtime customer and plastic pipe manufacturer shut down a few years ago, Manifold & Phalor's owner, Tom Creek, decided to hire much of its staff, set up its U.S. Die Mold division, and serve the blown-film die industry. It combined the company's welding and fabrication, general machining, and machine building divisions, all of which are located in the company's new 30,000-square-foot facility, which is three times the size of its former shop.

"This company has been providing services for 30-40 years, but we didn't begin to look at it as discrete business units until four or five years ago," Creek says. "When we were a smaller company, we were able to have all our staff focus on each project and service, but as we grew larger, it became more difficult to provide a high level of service if everyone was involved in each area. My plan for growth is to put people who are very knowledgeable in their technical area in charge of those areas, and so we decided to have the technical experts run each internal business group, and each has continued growing since then."

To further help its die mold division serve its customers, Manifold & Phalor's machine building division recently rebuilt a Giddings & Lewis Orion 2300 horizontal CNC machining center, which is large enough to handle a 5 ft cube of material. "It had proprietary controls that were 20 years old, and we just couldn't put it back into service with such old controls," Creek explains. "So we remanufactured it with new Fanuc controls, which gave us a fully functional, four-axis, horizontal machining center. We also installed a Renishaw probing and measuring system, which gives us much better measurement and control of our machining process. Also, the new controls are linked to our small server system, which consists of a Dell server running Windows NT on about 10-12 PCs."

Creek reports that the refurbished and more-capable Orion 2300 already is performing jobs for clients, and is one of the reasons that Manifold & Phalor's sales are up about 40% from a year ago. "We're able to process large castings, which are often back here from China," Creek says. "This machine helps us offer a variety of maintenance and repair services for all of North America, such as refurbishing blown film dies, which are used to make wine-in-box bags. Another customer, who runs a hot-forge press, brought a big chunk of it in for repair, and we were able to do a good job and stand by them."

Software Aids Retrofits

Whether they deploy new PLCs, motors or controllers, most retrofits of legacy machines now rely on some combination of microprocessors, software or networking. However, besides giving old machines new life, these data processing components can give them new capabilities, too.

"This is especially true for those  upgrading from electromechanical and older electronic systems," says Vincent DiGangi, senior partner at Connell Industries, a control system integrator in West Caldwell, N.J. "Upgrading to new digital control systems not only provides a big payback, but likely will keep many companies competitive."

So, while process system reliability is probably the most likely improvement that many of his customers seek, DiGangi also encourages them to look at the overall business improvements and return on investment (ROI) that control system upgrades can provide, such as improved output, product quality, uptime and production capacity.

Nathan Eisel, applications support engineer at Beckhoff Automation, reports that combining old machines and new controls is smoothed by using appropriate software, which can tie controls and hardware together from the SCADA system on down to legacy hardware even on the I/O level. He adds that PC-based control can simplify how old and new equipment are combined.

"Running control software on an industrial PC means machine builders and users can eliminate a lot of hardware steps they used to go through," he says. "For example, a barcode scanner previously plugged into a black box for fieldbus, and passed data through it and a brick PLC to an administrative computer. Now that scanner uses software to link directly to the PC, so doing a retrofit project like this is much simpler."